1. Field of the Invention
The present invention relates to resin compositions containing a saponified ethylene/vinyl acetate copolymer (hereinafter sometimes abbreviated as EVOH) which have improved heat stability.
2. Description of Related Art
EVOH has good gas barrier property. Also, molded products, such as films, sheets and bottles, which can be obtained by mnelt-extrusion molding of a blend composition comprising EVOH and another thermoplastic resin, and, if necessary, subsequently conducting stretching and/or heat-treating are excellent in gas barrier property and dynamic properties. Such features of the conventional blend compositions of EVOH and other various thermoplastic resins have been known. However, it has been known that such compositions, in general, are poor in heat stability, and accordingly, since they are likely to cause gel, scorch and heterogeneous phase-separation foreign bodies in the production of films, sheets, bottles, etc. by extrusion molding, the appearance of the products is seriously deteriorated due to the increase of such foreign bodies during a long-time processing. Particularly, although the blend compositions of EVOH and other various thermoplastic resins have the above-mentioned good properties, they can not be applied to extrusion molding at all, or even if they can be applied to that, they may be processed for only a short time. In order to dissolve such problems, Japanese examined patent publications Nos. Hei 5-6579 and Hei 6-18957 disclose a composition containing a hydrotalcite type compound, which, however, is not necessarily satisfactory.